(split) LDP v3.24 -> v3.29 の定型的な変更内容を反映。

[linuxjm/LDP_man-pages.git] / draft / man3 / getcwd.3

.\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" License.
.\" Modified Wed Jul 21 22:35:42 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified 18 Mar 1996 by Martin Schulze (joey@infodrom.north.de):
.\"   Corrected description of getwd().
.\" Modified Sat Aug 21 12:32:12 MET 1999 by aeb - applied fix by aj
.\" Modified Mon Dec 11 13:32:51 MET 2000 by aeb
.\" Modified Thu Apr 22 03:49:15 CEST 2002 by Roger Luethi <rl@hellgate.ch>
.\"
.\" Japanese Version Copyright (c) 1997 IMAMURA Nobutaka
.\"         all rights reserved.
.\" Translated Fri Feb 14 12:40:22 JST 1997
.\"         by IMAMURA Nobutaka <imamura@spp.hpc.fujitsu.co.jp>
.\" Modified Thu Dec 8 05:08:44 JST 1999
.\"         by Kentaro Shirakata <argrath@yo.rim.or.jp>
.\" Modified Sun Mar 12 21:08:44 JST 2000
.\"         by HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated 2001-01-29 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2002-03-23 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2002-10-17 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2007-01-01 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2008-08-21, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v3.07
.\"
.\" WORD: current working directory     ¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê
.\" WORD: LEGACY        ¡Ö²áµî¤Î̾»Ä(LEGACY)¡×
.\"
.TH GETCWD 3 2010-09-20 "GNU" "Linux Programmer's Manual"
.\"O .SH NAME
.SH ̾Á°
.\"O getcwd, getwd, get_current_dir_name \- Get current working directory
getcwd, getwd, get_current_dir_name \- ¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê̾¤Î¼èÆÀ
.\"O .SH SYNOPSIS
.SH ½ñ¼°
.nf
.B #include <unistd.h>
.sp
.BI "char *getcwd(char *" buf ", size_t " size );
.sp
.BI "char *getwd(char *" buf );
.sp
.B "char *get_current_dir_name(void);"
.fi
.sp
.in -4n
.\"O Feature Test Macro Requirements for glibc (see
.\"O .BR feature_test_macros (7)):
glibc ¸þ¤±¤Îµ¡Ç½¸¡ºº¥Þ¥¯¥í¤ÎÍ×·ï
.RB ( feature_test_macros (7)
»²¾È):
.sp
.in
.BR get_current_dir_name ():
.RS
_GNU_SOURCE
.RE
.sp
.BR getwd ():
.ad l
.RS 4
.PD 0
.TP 4
.\"O Since glibc 2.10:
glibc 2.10 °Ê¹ß:
.nf
_BSD_SOURCE ||
    (_XOPEN_SOURCE\ >=\ 500 ||
        _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED) &&
    !(_POSIX_C_SOURCE\ >=\ 200809L || _XOPEN_SOURCE\ >=\ 700)
.fi
.TP 4
.\"O Before glibc 2.10:
glibc 2.10 ¤è¤êÁ°:
_BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 ||
_XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
.PD
.RE
.ad b
.\"O .SH DESCRIPTION
.SH ÀâÌÀ
.\"O These functions return a null-terminated string containing an
.\"O absolute pathname that is the current working directory of
.\"O the calling process.
.\"O The pathname is returned as the function result and via the argument
.\"O .IR buf ,
.\"O if present.
¤³¤ì¤é¤Î´Ø¿ô¤Ï¡¢¸Æ¤Ó½Ð¤·¤¿¥×¥í¥»¥¹¤Î¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤Î
ÀäÂХѥ¹Ì¾ (absolute pathname) ¤¬Æþ¤Ã¤¿Ê¸»úÎó¤òÊÖ¤¹¡£
ÊÖ¤µ¤ì¤ëʸ»úÎó¤Ï NULL ¤Ç½ªÃ¼¤µ¤ì¤ë¡£
¥Ñ¥¹Ì¾¤Ï´Ø¿ô¤Î·ë²Ì¤È¤·¤ÆÊÖ¤µ¤ì¡¢°ú¿ô
.I buf
¤¬¤¢¤ë¾ì¹ç¤Ï
.I buf
·Ðͳ¤Ç¤âÊÖ¤µ¤ì¤ë¡£

.\"O The
.\"O .BR getcwd ()
.\"O function copies an absolute pathname of the current working directory
.\"O to the array pointed to by
.\"O .IR buf ,
.\"O which is of length
.\"O .IR size .
.BR getcwd ()
´Ø¿ô¤Ï¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤ÎÀäÂХѥ¹Ì¾¤ò
.I buf
¤Ç¼¨¤µ¤ì¤¿
.I size
ŤÎÇÛÎó¤Ë¥³¥Ô¡¼¤¹¤ë¡£
.PP
.\"O If the length of the absolute pathname of the current working directory,
.\"O including the terminating null byte, exceeds
.\"O .I size
.\"O bytes, NULL is returned, and
.\"O .I errno
.\"O is set to
.\"O .BR ERANGE ;
.\"O an application should check for this error, and allocate a larger
.\"O buffer if necessary.
½ªÃ¼¤Î NULL ¥Ð¥¤¥È¤â´Þ¤á¤¿¡¢¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤Î
ÀäÂХѥ¹Ì¾¤ÎŤµ¤¬
.I size
¥Ð¥¤¥È¤òĶ¤¨¤Æ¤¤¤ë¾ì¹ç¤Ï¡¢ÊÖ¤êÃͤȤ·¤Æ NULL ¤¬ÊÖ¤ê
.I errno
¤Ë
.B ERANGE
¤¬¥»¥Ã¥È¤µ¤ì¤ë¡£
¥¢¥×¥ê¥±¡¼¥·¥ç¥ó¤Ï¤³¤Î¥¨¥é¡¼¤ò¥Á¥§¥Ã¥¯¤·¡¢
ɬÍפ˱þ¤¸¤Æ¤è¤êŤ¤¥Ð¥Ã¥Õ¥¡¤òÍÑ°Õ¤¹¤Ù¤­¤Ç¤¢¤ë¡£
.PP
.\"O As an extension to the POSIX.1-2001 standard, Linux (libc4, libc5, glibc)
.\"O .BR getcwd ()
.\"O allocates the buffer dynamically using
.\"O .BR malloc (3)
.\"O if
.\"O .I buf
.\"O is NULL.
.\"O In this case, the allocated buffer has the length
.\"O .I size
.\"O unless
.\"O .I size
.\"O is zero, when
.\"O .I buf
.\"O is allocated as big as necessary.
.\"O The caller should
.\"O .BR free (3)
.\"O the returned buffer.
POSIX.1-2001 ɸ½à¤Î³ÈÄ¥¤È¤·¤Æ¡¢
Linux (libc4, libc5, glibc) ¤Ç¤Ï
.I buf
¤¬ NULL ¤Î¾ì¹ç¡¢
.BR getcwd ()
¤ÏɬÍפʥХåե¡¤ò
.BR malloc (3)
¤òÍѤ¤¤ÆưŪ¤Ë³ä¤êÅö¤Æ¤ë¡£
¤³¤Î¾ì¹ç¡¢
.I size
¤¬ 0 ¤Î¾ì¹ç¤ò½ü¤­¡¢¥Ð¥Ã¥Õ¥¡¤ÎŤµ¤Ï
.I size
¤È¤Ê¤ë¡£
.I size
¤¬ 0 ¤Î¾ì¹ç¤Ë¤ÏɬÍפÊÂ礭¤µ¤¬³ÎÊݤµ¤ì¤ë¡£
¸Æ¤Ó½Ð¤·Â¦¤Ç¡¢ÊÖ¤µ¤ì¤¿¥Ð¥Ã¥Õ¥¡¤ò
.BR free (3)
¤¹¤Ù¤­¤Ç¤¢¤ë¡£

.\"O .BR get_current_dir_name ()
.\"O will
.\"O .BR malloc (3)
.\"O an array big enough to hold the absolute pathname of
.\"O the current working directory.
.\"O If the environment
.\"O variable
.\"O .B PWD
.\"O is set, and its value is correct, then that value will be returned.
.BR get_current_dir_name ()
¤Ï¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤ÎÀäÂХѥ¹Ì¾¤ò¼ý¤á¤ë¤Î¤Ë
½½Ê¬¤ÊÂ礭¤µ¤ÎÇÛÎó¤ò
.BR malloc (3)
¤Ç³ÍÆÀ¤¹¤ë¡£´Ä¶­ÊÑ¿ô
.B PWD
¤¬ÀßÄꤵ¤ì¤Æ¤ª¤ê¤½¤ÎÃͤ¬Àµ¤·¤±¤ì¤Ð¡¢¤½¤ÎÃͤ¬ÊÖ¤µ¤ì¤ë¡£
.\"O The caller should
.\"O .BR free (3)
.\"O the returned buffer.
¸Æ¤Ó½Ð¤·Â¦¤Ç¡¢ÊÖ¤µ¤ì¤¿¥Ð¥Ã¥Õ¥¡¤ò
.BR free (3)
¤¹¤Ù¤­¤Ç¤¢¤ë¡£

.\"O .BR getwd ()
.\"O does not
.\"O .BR malloc (3)
.\"O any memory.
.\"O The
.\"O .I buf
.\"O argument should be a pointer to an array at least
.\"O .B PATH_MAX
.\"O bytes long.
.\"O If the length of the absolute pathname of the current working directory,
.\"O including the terminating null byte, exceeds
.\"O .B PATH_MAX
.\"O bytes, NULL is returned, and
.\"O .I errno
.\"O is set to
.\"O .BR ENAMETOOLONG .
.BR getwd ()
¤Ï
.BR malloc (3)
¤Ë¤è¤ë¥á¥â¥ê³ÍÆÀ¤ò°ìÀڹԤʤï¤Ê¤¤¡£
.I buf
°ú¿ô¤Ï¾¯¤Ê¤¯¤È¤â
.B PATH_MAX
¥Ð¥¤¥È¤ÎŤµ¤ò»ý¤ÄÇÛÎó¤Ø¤Î¥Ý¥¤¥ó¥¿¤Ç¤¢¤ëɬÍפ¬¤¢¤ë¡£
½ªÃ¼¤Î NULL ¥Ð¥¤¥È¤â´Þ¤á¤¿¡¢¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤Î
ÀäÂХѥ¹Ì¾¤ÎŤµ¤¬
.B PATH_MAX
¥Ð¥¤¥È¤òĶ¤¨¤Æ¤¤¤ë¾ì¹ç¡¢
NULL ¤¬ÊÖ¤µ¤ì¡¢
.I errno
¤Ë
.B ENAMETOOLONG
¤¬ÀßÄꤵ¤ì¤ë¡£
.\"O (Note that on some systems,
.\"O .B PATH_MAX
.\"O may not be a compile-time constant;
.\"O furthermore, its value may depend on the file system, see
.\"O .BR pathconf (3).)
.\"O For portability and security reasons, use of
.\"O .BR getwd ()
.\"O is deprecated.
(¥·¥¹¥Æ¥à¤Ë¤è¤Ã¤Æ¤Ï¡¢
.B PATH_MAX
¤Ïɬ¤º¤·¤â¥³¥ó¥Ñ¥¤¥ë»þ¤Ë·è¤Þ¤ëÄê¿ô¤Ç¤Ï¤Ê¤¤ÅÀ¤ËÃí°Õ¤¹¤ë¤³¤È¡£
¤Þ¤¿¡¢¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ë°Í¸¤¹¤ë¾ì¹ç¤â¤¢¤ë¡£
.BR pathconf (3)
¤ò»²¾È¡£)
°Ü¿¢À­¤È¥»¥­¥å¥ê¥Æ¥£¾å¤ÎÍýͳ¤«¤é¡¢
.BR getwd ()
¤ÎÍøÍѤϿ侩¤µ¤ì¤Ê¤¤¡£
.\"O .SH "RETURN VALUE"
.SH ÊÖ¤êÃÍ
.\"O On success, these functions return a pointer to a string containing
.\"O the pathname of the current working directory.
.\"O In the case
.\"O .BR getcwd ()
.\"O and
.\"O .BR getwd ()
.\"O this is the same value as
.\"O .IR buf.
À®¸ù¤¹¤ë¤È¡¢¤³¤ì¤é¤Î´Ø¿ô¤Ï¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤ÎÀäÂХѥ¹Ì¾
¤¬Æþ¤Ã¤¿Ê¸»úÎó¤Ø¤Î¥Ý¥¤¥ó¥¿¤òÊÖ¤¹¡£
.BR getcwd ()
¤È
.BR getwd ()
¤Î¾ì¹ç¡¢ÊÖ¤êÃͤÏ
.I buf
¤ÈƱ¤¸Ãͤˤʤ롣

.\"O On failure, these functions return NULL, and
.\"O .I errno
.\"O is set to indicate the error.
.\"O The contents of the array pointed to by
.\"O .I buf
.\"O are undefined on error.
¼ºÇÔ¤·¤¿¾ì¹ç¡¢¤³¤ì¤é¤Î´Ø¿ô¤Ï NULL ¤òÊÖ¤·¡¢
.I errno
¤Ë¥¨¥é¡¼¤ò¼¨¤¹ÃͤòÀßÄꤹ¤ë¡£
.I buf
¤¬»Ø¤¹ÇÛÎó¤ÎÆâÍƤÏ̤ÄêµÁ¤Ç¤¢¤ë¡£
.\"O .SH ERRORS
.SH ¥¨¥é¡¼
.TP
.B EACCES
.\"O Permission to read or search a component of the filename was denied.
¥Õ¥¡¥¤¥ë̾¤Î¹½À®Í×ÁǤËÂФ¹¤ëÆɤ߹þ¤ß¤¢¤ë¤¤¤Ï¸¡º÷¤Î¸¢¸Â¤¬¤Ê¤¤¡£
.TP
.B EFAULT
.\"O .I buf
.\"O points to a bad address.
.I buf
¤¬ÉÔÀµ¤Ê¥¢¥É¥ì¥¹¤ò»Ø¤·¤Æ¤¤¤ë¡£
.TP
.B EINVAL
.\"O The
.\"O .I size
.\"O argument is zero and
.\"O .I buf
.\"O is not a null pointer.
.I size
°ú¿ô¤¬ 0 ¤«¤Ä¡¢
.I buf
°ú¿ô¤¬ NULL ¥Ý¥¤¥ó¥¿¤Ç¤Ê¤¤¡£
.TP
.B EINVAL
.\"O .BR getwd ():
.\"O .I buf
.\"O is NULL.
.BR getwd ():
.I buf
¤¬ NULL ¤Ç¤¢¤ë¡£
.TP
.B ENAMETOOLONG
.\"O .BR getwd ():
.\"O The size of the null-terminated absolute pathname string exceeds
.\"O .B PATH_MAX
.\"O bytes.
.BR getwd ():
ÀäÂХѥ¹Ì¾¤¬Æþ¤Ã¤¿ NULL ½ªÃ¼¤µ¤ì¤¿Ê¸»úÎó¤ÎŤµ¤¬
.B PATH_MAX
¥Ð¥¤¥È¤òĶ¤¨¤Æ¤¤¤ë¡£
.TP
.B ENOENT
.\"O The current working directory has been unlinked.
¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤¬ºï½ü¤µ¤ì¤Æ¤¤¤ë¡£
.TP
.B ERANGE
.\"O The
.\"O .I size
.\"O argument is less than the length of the absolute pathname of the
.\"O working directory, including the terminating null byte.
.\"O You need to allocate a bigger array and try again.
.I size
°ú¿ô¤ÎÃͤ¬¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤ÎÀäÂХѥ¹Ì¾¤ÎŤµ¤è¤ê¾®¤µ¤¤¡£
Ťµ¤Ë¤Ïʸ»úÎó¤Î½ªÃ¼¥Ð¥¤¥È¤â´Þ¤Þ¤ì¤ë¡£
¤è¤êÂ礭¤¤ÇÛÎó¤ò³ÎÊݤ·¤Æ¤â¤¦°ìÅټ¹Ԥ¹¤ëɬÍפ¬¤¢¤ë¡£
.\"O .SH "CONFORMING TO"
.SH ½àµò
.\"O .BR getcwd ()
.\"O conforms to POSIX.1-2001.
.BR getcwd ()
¤Ï POSIX.1-2001 ¤Ë½àµò¤·¤Æ¤¤¤ë¡£
.\"O Note however that POSIX.1-2001 leaves the behavior of
.\"O .BR getcwd ()
.\"O unspecified if
.\"O .I buf
.\"O is NULL.
POSIX.1-2001 ¤Ï¡¢
.I buf
¤¬ NULL ¤Î¾ì¹ç¤Î
.BR getcwd ()
¤ÎÆ°ºî¤òµ¬Äꤷ¤Ê¤¤¤Þ¤Þ¤È¤·¤Æ¤¤¤ë¡£

.\"O .BR getwd ()
.\"O is present in POSIX.1-2001, but marked LEGACY.
.BR getwd ()
¤Ï POSIX.1-2001 ¤Ë¸ºß¤·¤Æ¤¤¤ë¤¬¡¢¡Ö²áµî¤Î̾»Ä(LEGACY)¡×¤È¤µ¤ì¤Æ¤¤¤ë¡£
.\"O POSIX.1-2008 removes the specification of
.\"O .BR getwd ().
.\"O Use
.\"O .BR getcwd ()
.\"O instead.
.\"O POSIX.1-2001
.\"O does not define any errors for
.\"O .BR getwd ().
POSIX.1-2008 ¤Ç¤Ï¡¢
.BR getwd ()
¤Î»ÅÍͤ¬ºï½ü¤µ¤ì¤Æ¤¤¤ë¡£
Âå¤ï¤ê¤Ë
.BR getcwd ()
¤ò»È¤¦¤³¤È¡£
POSIX.1-2001 ¤Ï
.BR getwd ()
¤Ë´Ø¤¹¤ë¥¨¥é¡¼¤òÄêµÁ¤·¤Æ¤¤¤Ê¤¤¡£

.\"O .BR get_current_dir_name ()
.\"O is a GNU extension.
.BR get_current_dir_name ()
¤Ï GNU ³ÈÄ¥¤Ç¤¢¤ë¡£
.\"O .SH NOTES
.SH Ãí°Õ
.\"O Under Linux, the function
.\"O .BR getcwd ()
.\"O is a system call (since 2.1.92).
Linux ¤Ç¤Ï (2.1.92 °Ê¹ß)¡¢
.BR getcwd ()
¤Ï¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ç¤¢¤ë¡£
.\"O On older systems it would query
.\"O .IR /proc/self/cwd .
¸Å¤¤¥·¥¹¥Æ¥à¤Ç¤Ï
.I /proc/self/cwd
¤ò»²¾È¤¹¤ë¡£
.\"O If both system call and proc file system are missing, a
.\"O generic implementation is called.
.\"O Only in that case can
.\"O these calls fail under Linux with
.\"O .BR EACCES .
¥·¥¹¥Æ¥à¥³¡¼¥ë¤â proc ¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤â¤Ê¤¤¾ì¹ç¡¢
°ìÈÌŪ¤Ê¼ÂÁõ¤¬¸Æ¤Ó½Ð¤µ¤ì¤ë¡£
¤³¤Î¾ì¹ç¤Ë¤ª¤¤¤Æ¤Î¤ß¡¢(Linux ¤Ç¤Ï) ¤³¤Î´Ø¿ô¤Ï
.B EACCES
¤Ç¼ºÇÔ¤¹¤ë²ÄǽÀ­¤¬¤¢¤ë¡£
.LP
.\"O These functions are often used to save the location of the current working
.\"O directory for the purpose of returning to it later.
.\"O Opening the current
.\"O directory (".") and calling
.\"O .BR fchdir (2)
.\"O to return is usually a faster and more reliable alternative when sufficiently
.\"O many file descriptors are available, especially on platforms other than Linux.
¤³¤ì¤é¤Î´Ø¿ô¤Ï¤·¤Ð¤·¤Ð¥«¥ì¥ó¥È¥ï¡¼¥­¥ó¥°¥Ç¥£¥ì¥¯¥È¥ê¤Î°ÌÃÖ¤òÊݸ¤·¡¢
¸å¤ÇÌá¤Ã¤Æ¤¯¤ë¤¿¤á¤ËÍøÍѤµ¤ì¤ë¡£
̤»ÈÍѤΥե¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤¬½½Ê¬¤¢¤ë¾ì¹ç¤Ï¡¢
¸½ºß¤Î¥Ç¥£¥ì¥¯¥È¥ê (".") ¤ò³«¤¤¤Æ
.BR fchdir (2)
¤ò¸Æ¤Ó½Ð¤¹¤Û¤¦¤¬ÉáÄ̤Ϲ⮤ǿ®ÍêÀ­¤¬¤¢¤ë¡£
ÆÃ¤Ë Linux °Ê³°¤Î¥×¥é¥Ã¥È¥Õ¥©¡¼¥à¤Î¾ì¹ç¤Ï¤½¤¦¤Ç¤¢¤ë¡£
.\"O .SH "SEE ALSO"
.SH ´ØÏ¢¹àÌÜ
.BR chdir (2),
.BR fchdir (2),
.BR open (2),
.BR unlink (2),
.BR free (3),
.BR malloc (3)